The FAA has issued a flight advisory for potentially unreliable GPS signals in the vicinity of Beatty, Nev., through Aug. 26.

During testing, the GPS signal may be unreliable or unavailable within a 285 nautical-mile radius centered at 360055N/1173719W or the BTY VOR 227.7-degree radial at 57.2 nm at Flight Level 400 and above, decreasing in area with a decrease in altitude to a radius of 240 nm at Flight Level 250, a radius of 165 nm at 10,000 feet msl, a radius of 130 nm at 4,000 feet agl, and a radius of 50 nm at 50 feet agl.

Pilots are encouraged to report anomalies to the appropriate air route traffic control center to help determine the extent of signal degradation. Please share your reports with AOPA.

Notams will be published at least 24 hours in advance of tests, but may change with little or no notice. Pilots are encouraged to check notams frequently for changes to operations in the area.

Tests will be intermittent within the stated times, the FAA said. See the flight advisory for scheduled dates and times.